Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan, ensuring the sides are evenly coated so the cake releases cleanly after baking.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. This step distributes the leavening evenly and prevents clumps in the batter.
In a large bowl, cream the softened butter and granulated sugar until light and fluffy. The mixture should turn pale and airy, which helps the cake rise with a tender crumb.
Beat in the eggs one at a time, mixing well after each addition. Add the vanilla extract and continue to mix until the batter looks smooth and cohesive.
Alternately add the dry ingredients and buttermilk to the butter mixture, beginning and ending with the dry ingredients. Mix just until combined—overmixing can lead to a dense cake, so stop as soon as no streaks of flour remain.
Gently fold in the chopped strawberries. Their juices will lightly streak the batter, and folding carefully helps keep the fruit intact so it bakes into soft, juicy pockets.
Pour the batter into the prepared pan and smooth the top with a spatula to ensure even baking.
Bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean. The edges should be lightly golden, and the surface should spring back when touched.
Let the cake cool in the pan for 10 minutes, allowing it to firm slightly before transferring it to a wire rack. Cool completely so the whipped cream topping stays light and stable.
For the whipped cream, beat the heavy cream, powdered sugar, and vanilla extract until stiff peaks form. Chilling the bowl and beaters beforehand helps the cream whip faster and hold structure better.
Once the cake has fully cooled, spread the whipped cream evenly over the top, keeping it fluffy rather than pressing it down.
Sprinkle the crushed Oreo cookies generously over the whipped cream, allowing some larger pieces for crunch and smaller crumbs to settle into the surface.
Serve chilled or at room temperature. Chilling enhances the contrast between the creamy topping and the soft cake, while room temperature serving highlights the cake’s buttery texture.
